I know a lot of you guys think I'm being excessively contrarian. But that is a huge issue when it comes to asking people to dramatically change their lifestyles, suffer immediate economic hardship, etc.Scientists have amassed a vast body of knowledge regarding the physical world. Unlike many areas of science, however, scientists who study the Earth’s climate cannot build a “con- trol Earth” and conduct experiments on this Earth in a lab. To experiment with the Earth, scientists instead use this accumu- lated knowledge to build climate models, or “virtual Earths.” In studying climate change, these virtual Earths serve as an im- portant way to integrate different kinds of knowledge of how the climate system works.
It's like saying that you're going to do a clinical trial to approve a new drug but instead of doing it with real people you're going to construct "virtual people" in a super computer and give them the new drug in a "virtual sense" to see what the computer models say it's going to do in terms of safety and effectiveness.
But at least they are hinting at the problem with climate "science." I give them credit for that.
P.S., the reason I put "science" in quotes like that is that if you're really strict about it climate study is not science. Science requires controlled experiments on the actual thing; not model simulations. It's really, in the strictest sense, climate observational study.
And I'm not making that up people. I'm really not.
Oh...I haven't figured out how to link directly to the quote I used. You have to go to http://nca2014.globalchange.gov/report#section-1946" onclick="window.open(this.href);return false;, click on "FAQs," then do a search on "How reliable are the computer models of the Earth’s climate?" That should bring you to the discussion on page 820.